1. Field of the Invention
This invention relates generally to improvements in high pressure tubular connections and more particularly, but not by way of limitation, to improvements in high pressure swivel joints.
2. Description of the Prior Art
The prior art contains a number of teachings of high pressure tubular swivel joints. Typical of such swivel joints is that disclosed in U.S. Pat. No. 3,347,570 to H. W. Roessler. In general, the prior art high pressure tubular swivel joints employ elastomeric dynamic annular seals to provide effective sliding sealing engagement between the rotating and non-rotating elements of the swivel joints. The use of elastomeric ompounds in the construction of such dynamic annular seals is dictated by the excellent sealing characteristics of such materials.
When the fluids being passed through the prior art swivel joints, employing elastomeric annular seals, are highly corrosive in nature and contain hydrogen sulfide or the like, seal life in the swivel joints is adversely affected. The present invention provides seal structure in which the dynamic seal is isolated from corrosive fluids, such as those containing hydrogen sulfide, passing through the swivel joint by an annular chamber positioned therebetween containing a liquid which is unaffected by contact with hydrogen sulfide and does not attack the elastomeric material from which the resilient dynamic annular seal is constructed.